Malaysian maritime authorities were searching on Tuesday for three crew missing from a Gabon-registered tanker a day after the 26-year-old vessel caught fire in waters off the southern coast.
The ship, Pablo, sailing from China to Singapore to pick up crude oil, was not carrying cargo and there were no reports of an oil spill, the Malaysian Maritime Enforcement Agency (MMEA) said.
However, it did not rule out the chance that the men, two Indian nationals and a Ukrainian, could still be aboard, as smoke made it unsafe to inspect the vessel after the fire appeared to have stopped by afternoon.
"There is a possibility that the three are still on the boat," Saiful Lizan Ibrahim, a top MMEA official, told a news conference in the southern state of Johor.
The remaining 25 crew were rescued, including 23 picked up by two ships nearby, authorities said. Four had serious injuries.
Rescuers were scouring an area of 71 nautical miles in the search for the missing crew.
Pablo Union Shipping, the Marshall Islands-based owner of the vessel, according to shipping databases, could not be located to seek comment. The vessel's insurers were unknown.
The ship, which had been used to carry Iranian oil to China since at least the middle of 2022, last delivered Iranian crude to the eastern port of Qingdao in late January, said Emma Li, a China analyst at Vortexa.
Built in 1997, the vessel had been anchored off China's eastern port of Zhoushan for about two months between February and April, before sailing towards an anchorage area off Singapore and Malaysia, data from Kpler and Vortexa showed.
The MMEA said it began search and rescue operations after being notified of the fire on Monday at 4 p.m. (0800 GMT), and was investigating its cause.
Despite tough sanctions re-imposed by former U.S. President Donald Trump on Iran's oil exports, its supplies have been slipping into China since late 2019, masked as coming from Oman, Malaysia and the United Arab Emirates, traders and analysts say.
Beijing has repeatedly condemned Washington's unilateral sanctions and defended trade with Iran as normal business practice in line with international law.
(Reporting by Rozanna Latiff in Kuala Lumpur and Muyu Xu and Chen Aizhu in Singapore; Editing by Clarence Fernandez)